Air puffer for circuit breakers



April 2, 1957 G. A. WILSON AIR PURFER RoR CIRCUIT BREAKERS 2Sheets-Sheet l Filed Aug. 31, 1953 Ap 2, 1957 G. A. WILSON AIR PUFFERFOR CIRCUIT BREAKERS 2 Sheeis-Sheet 2 Filed Augf 31, 1953 .DJ NE' IN VENTOR. isoler/ //aa/v United States Patent O 1 2,787,686 AIR PUFFER FORCIRCUIT BREAKERS George A. Wilson, Springfield, Pa., assignor to I-T-ECircuit Breaker Company, Philadelphia, Pa. Application August 31, 1953,Serial No. 377,527 8 Claims. (Ci. 20G- 148) My invention is related toair puffers for circuit breakers and is more particularly directed to anovel air puifer which operates on a pantograph principle requiring onlythe major parts of a vane and a casing.

Air puiers are used in coordination with circuit breakers in order toprovide an auxiliary means to transfer the arc from the cooperatingcontacts toward and into the arc extinction means and may also be usedto extinguish the arc. The air putfer device does not require storedenergy for either its mechanical operation or source of air to be blownagainst the arc. The device is preferably pivotally connected to themovable contact arm or bridge in such a manner that the opening movementof the circuit breaker will supply the motivating force for itsoperation.

It will be noted that the air putter is primarily applicable to largecircuit breakers which may require a blow out coil arrangement in orderto lift and move the arc into the arc extinguishing means. However, withthis type of breaker, the interruption of a relatively low magnitude offault current may result in a magnitude of ampere turns for the blow outcoil which is insufficient to create a large enough magnetic force topull or force the arc off the cooperating contacts on to the arc hornsand into the arc extinguishing means.

By providing an air puifer which is so constructed that it is operatedboth independent of the magnitude of the fault current being interruptedand does not require an auxiliary source of energy, it is possible toforce the arc off the movable contacts even though the magnetic forcecreated by the blow out coil is insuicient to properly move the arc.That is, by providing an arrangement in which the putter is operateddirectly from the movement of the bridge, its force and effect on thearc will be independent of the magnitude of the fault current and hencewill operate equally well on the interruption of either a fault currentor a short circuit current.

Heretofore, air putters have been constructed utilizing apiston-cylinder construction. However, this type of construction hasmany disadvantages which are overcome by the device of my invention. Forexample, in the prior art arrangement, the air movement was notgenerated close to the point of the arcing contacts and hence, itseffectiveness on the arc is greatly reduced. Furthermore, this type ofarrangement required a duct or passageway to guide the air flow from itspoint of generation to the arcing contacts thereby greatly reducing theforce and effect of the air stream. Also, due to the fact that thepiston-cylinder type of arrangement relied solely on straight-linemotion, it was impossible to vary the rate of air flow which could beobtained from the air puifer device.

Since the primary function of the air putier is to lift the arc oii thearcing contacts, it is desirable to have maximum rate of air flow duringthe initial portion of the opening stroke. However, this sequence of airHow is not possible with the prior art straight-line movement whichsupplies a steady air flow irrespective of the movement of the bridge.

A further disadvantage inherent in the straight-line movement of thepiston-cylinder arrangement is that a portion of the air putter had tobe positioned between the rear portion of the line terminals or studsand hence, might be conducive to an electrical failure to ground.

Furthermore, the prior art arrangement required a 2,787,686 PatentedApr. 2, 1957 multiplicity of parts which are relatively complex inconstruction and require extensive alteration to the circuit breakermounting front.

With the novel air putter of my invention, I overcome all of thedisadvantages of the prior art arrangement and obtain desirableoperating characteristics which were not heretofore possible.

My novel air puier is comprised of a casing and a Vane movable therebyand therein. The casing is pivotally mounted on the bridge of thecircuit breaker and one end of the vane is pivotally mounted on thelower terminal of the circuit breaker. In addition, the intermediatepoint of the vane is pivotally mounted on the casing. The casing isprovided to a molding having parallel sides being substantially V-shapedwith arcuate upper portions with one straight side on the arcuate endportions of the side being joined.

The arcuate connecting member between the arcuatel portions of thespaced parallel V-shaped sides of the casing is provided with an openingwhich forms the spout through which the air stream can be directed tothe arcing contacts of the circuit breaker.

By adjusting the angle between the line formed by the common pivot ofthe casing on the bridge and the line formed by the common pivot betweenthe casing and vane and the vane pivot on the lower terminal, the rateof air ow at any point within the opening stroke can be pre-adjusted.

ln addition to this feature, the pantograph arrangement will providemultiple motion so that the magnitude of angular velocity of the vanewill be greater than the magnitude of angular velocity of the bridge.Hence, with my novel arrangement, it is not only possible to obtain morerapid movement of the vane, but it is possible to obtain both rapidmovement of the vane and also to control its rate of movement at anypoint within the stroke. Thus, for example, when the above mentionedangle is an acute angle at the start of the opening stroke, then therate of movement of the vane, and resulting air Bow, will be at amaximum at the start of the opening movement.

Thus, my novel apparatus can be adjusted to deliver the maximum rate ofair ow at the beginning of the opening stroke which is the time when theair stream is most instrumental in moving the arc off the arcingcontacts and is therefore the precise time within the opening strokewhen maximum air ow is needed.

Further advantages are achieved with the pantograph system of my novelair pufler.

Since the casing is not restricted to straight line movement, the spoutthereof can be initially positioned under the upper terminal. However,since it will follow a slightly arcuate path, the stream of airemanating therefrom is not trapped under the terminal and hence, is

blown into the area of the arcing contacts where it is most effective.That is, although the spout initially guides the air stream directly onthe cooperating surfaces of the cooperating contacts, it Wilisubsequently follow the arc out as the circuit breaker' is openedthereby exerting a force where it is most needed. f

The inherent structure of the above mentioned casing with the spoutpositioned on the top thereof, enables the pufer to generate a stream ofair close to the arcing contacts thereby greatly increasing theefficiency of the air putter since the necessity of either providingguiding ducts or excess Wind friction to reduce the rate of flow iseiminated. Also, the fact that the stream of air is directly applied tothe arcing contacts will insure a more prompt delivery thereof with agreater volume of air at a higher velocity.

In view of the fact that my novel air putter only requires two majorparts, namely the vane and casing, the

unit has the advantage of both eXtreme simplicity and requires a minimumnumber of connecting points to the circuit breaker. Thus, my novel unitcan be adapted to a standard circuit breaker with a minimum number ofalterations thereof.

Accordingly, the air puller of my invention overcomes the disadvantagesof the prior art and has many desirable features which were notheretofore obtainable.

An object of my invention is to provide an air puller for circuitbreakers which is comprised of a vane and a casing which operate on apantograph principle.

Another object of my invention is to provide a vanecasing arrangementwhich will generate a stream of air on the arcing contacts when thecircuit breaker is opened.

Another object of my invention is to provide an air puller comprised ofa vane and casing wherein the casing is pivotally mounted on the bridge.The vane is pivotaily mounted 011 the lower terminal and the vane andcasing pivotally mounted to each other.

Still another object of my invention is to provide a pantograph type airpuer having a spout which moves from under the upper terminal during theopening oper; tion of the circuit breaker.

Another object of my invention is to provide a relatively simple airpuller which requires a minimum number of alterations to the circuit'breaker for the mounting thereon.

Another object of my invention is to provide an are transfer andextinguishing means for a circuit breaker which will generate a streamof air close to the arcing contacts.

Another object of my invention is to provide an are 'ransferring meanswhich is operated by the motion of the bridge of the circuit breaker toprovide a direct stream of air on the arc-ing contacts thereof.

A still further object of my invention is the adaption of a circuitbreaker with a putter device which provides prompt delivery of a largevolume of air at high velocity.

Still another object of my invention is to provide a 4)autograph airputlier which can be selectively mounted to obtain a predetermined rateof air ow.

Another object of my invention is to provide an air putter which can beselectively mounted to control the rate of air llow at any point withinthe opening stroke of the circuit breaker.

Another object of my invention is to provide an arc transferring meanscontrolled and operated by the movement of the bridge of the circuitbreaker in which the maximum rate of air llow will occur at the start ofthe opening movement of the bridge.

A still further object of my invention is to provide a construction foran air puller which can be mounted adjacent to the bridge of a circuitbreaker and kept away from the rear of the upper and lower terminals ofthe circuit breaker.

These and other objects of my invention will be apparent, to thoseskilled in the art, from the following desciption when taken inconnection with the drawings in which:

Figure l is a side view illustrating the position of my novel air pulerwhen the bridge of the circuit breaker is in the closed position.

Figure 2 is a side view similar to Figure l illustrating the position ofmy novel air pulier when the bridge of the circuit breaker is in theopen position.

Figure 3 is a top view of the air putter of my invention seen in Figuresl and 2 illustrating the manner in which this unit can be connected andsecured to the bridge of the circuit breaker.

In the illustration of my invention, I have shown a single pole circuitbreaker it) having upper terminal 11 and lower terminal 12. A stationarycontact 13 is electrically connected to the upper terminal 11 and thebridge 14 is pivotally connected at pin 15 to the lower terminal 12. Thebridge 14 is provided with a movable contact and cor ed of two parallelsides i7 and 1S, which have a tf-shaped configuration with an arcuatetop sur face.

Left hand sides of the wall 17 and 18 are joined by the tlat portion 19and the upper arcuate portions of the ,f-s sides Tf? and ,t3 are joinedby the arcuate connecting member The arcuate upper portion 29 of thecasing 25 is provi' d with a spout 32 at the front end thereof whichcommunicates with the interior of the casing The spout 32 is positionedimmediately below the cooperating contacts ifi-i3d when the bridge 14 isin the closed position of Figure l.

The casing 2S comprised of the parallel V-shaped sides 7' and l?. andthe top and end portions 19 and 2G is a relatively simple constructionwhich may be a molding or any desirable construction. lt will be notedthat the right hand end 2'7 of the casing 25 may be opened as the vane2G, hereinafter more fully described, will serve as the end wall. Theabove described casing 25 forms the rst major part of my novel airpuller. The casing 25 is provided with an extension 2 which is pivotallyconnected to the bridge 12 by the pin 26.

The second major part of my invention of a novel air puiler is the vane23 which is pivotally mounted at one end by the pin 29 on the lowerterminal 12. The vane is also pivotally mounted at a point intermediateits extreme ends by means of the pin 30 to the lower portion of theeasing 25. The vane 28 is provided with a cut out portion to receive thegasket 31 which properly seals the vane with respect to the casing 25 sothat there will be no air flow to the left during the opening motion ofthe circuit breaker 10.

Since the end cross-sectional view of the casing 25 is U-shaped, thecircular gasket 3l will also be U-shaped.

The operation of the air puller is as follows: On the occurrence of afault or short circuit on the line, the bridge 14 will be moved in acounterclockwise direction around its pivot point 15 in a manner wellknown in the art. Since the casing 25 is pivotally secured thereto atthe pivot point 26, the casing will also be rocked to the left. Due tothe pivotal connection 30 between the casing 25 and the vane 28, thevane will also be pulled toward the left. However, since the vane 28 hasa stationary pivot 29, it will have an arcuate movement about its fixedcenter whereas the movement of the casing 2S will be limited due to itspivot points 26 and 30. Hence, even through the vane 28 and casing 25are both moved to the left, the vane 28 will have relative movement withrespect to the casing 25 and hence, will be moved from the right handportion thereof toward the left hand portion thereof. rl`he boundariesof the casing will be contiguous to the vane at each angular position asit moves counterclockwise from the right side of the casing 25 to theleft side thereof.

This sweeping movement of the vane 23 will urge the air housed withinthe casing 25 to ilow out of the spout 32 toward the cooperatingcontacts 13-13a- Thus, an air stream will be directly exerted on the arcwhich emanates from the cooperating contact thereby causing it to liftott the Contact and be transferred to the are horn and into the arcchute not shown).

The final position of the air putter 1.6, when the circuit breaker is inthe open position is illustrated in Figure 2. It will be noted bycomparison of Figures l andl 2 that the spout 32, although initiallypositioned under the upper line terminal 11, moves out from under thisunit so that the air is not trapped thereunder where it would ordinarilybe inetective, but instead will follow the arc aS it is elongated duringthe opening movement of the bridge 14.

It will be noted that the pantograph arrangement of the air puer 16created by the stationary pivot 16 and the movable pivots 26, 30provides a multiplied motion tor the vane 28 with respect to the bridge14.

In the particular arrangement shown in Figures l and 2, thc magnitude ofthe angular Velocity of the vane 28 is approximately 50 percent greaterthan the angular velocity of the bridge 14. Thus, this multiple actionpermits both a greater value of air to be forced on the arc and alsoprovides for increasing the rate of air liow.

It will be noted that the air putter has its primary utility when thecircuit breaker is required to interrupt a relatively small faultcurrent. That is, if the circuit breaker ordinarily relies on a blow outcoil to lift the arc for the cooperating contacts 13-13a, the ampereturns of thc blow out coil may not create a suihcient magnetic force tolift the arc. Thus, in order to insure that the arc will be lifted intothe arc extinguishing means when the circuit breaker opens on arelatively small fault, the air putter 16 will provide a stream of airwhich will force the arc oft the cooperating contacts and into the arcchute. It is desirable that this happens during the initial part of theopening stroke so that the arc can be extinguished as soon as possible.

With my novel air putter, it is possible to control the rate of air flowwithin the point of the opening stroke so that a predetermined maximumrate of air How will occur at the initial part of the opening stroke.

The angle formed by the line adjoining the pivots 26-3t and the pivots29-30 when the bridge 14 is in the closed position will govern the rateof the air flow at any point in the opening stroke. Thus, for example,by making this angle an acute angle, when the circuit breaker is in theclosed position, the rate of air ow through the spout 32 of the pufrer16 will be at a maximum at the start of the opening stroke therebymaking the unit more eiicient, since the air is most eiectively usedearly in the stroke when the arc is initially created.'

Accordingly, I have provided a novel design for air puffers whichrequires only a vane and a casing whereby a large rate of air ow at theinitial point of the opening stroke can be directly applied to thecooperating contacts.

In the foregoing, I have described my invention only in connection withpreferred embodiments thereof. Many variations and modifications of theprinciples of my invention within the scope of the description hereinare obvious. Accordingly, I prefer to be bound not by the specificdisclosure herein but only by the appending claims.

I claim:

l. An air puifer for a circuit breaker comprising a casing and a vane;said casing pivotally mounted on a bridge of said circuit breaker; saidvane pivotally mounted on one terminal of said circuit breaker; saidvane also pivotally mounted on said casing; said vane and said casingboth having angular movement during the opening movement of said bridge.

2. An air putter for a circuit breaker comprising a casing and a vane;said casing pivotally mounted on a bridge of said circuit breaker; saidvane pivotally mounted on one terminal of said circuit breaker; saidvane also pivotally mounted on said casing; said vane and said casingboth having angular movement during the opening movement of said bridge;said vane having movement relative to said casing.

3. An air puffer for a circuit breaker comprising a casing and a vane;said casing pivotally mounted on a bridge of said circuit breaker; saidvane pivotally mounted on one terminal of said circuit breaker; saidvane also pivotally mounted on said casing; said vane and said casingboth having angular movement during the opening movement of said bridge;said vane having movement relative to said casing; said vane having amagnitude of angular velocity greater than the angular Velocity of saidbridge.

4. In a circuit breaker having an upper and lower terminal; a bridge anda pair of cooperating contacts mounted on said upper terminal; saidbridge pivotally mounted on said lower terminal; the other of saidcooperating contacts mounted on the free end of said bridge; an airputter comprising a casing and a vane; said casing pivotally mounted onsaid bridge; said vane pivotally mounted on said lower terminal; saidvane pivotally mounted on said casing; :said casing having a spoutpositioned below said cooperating contacts when said cooperatingcontacts are engaged.

5. In a circuit breaker having an upper and lower terminal; a pair ofcooperating contacts and a bridge;

one end of said bridge pivotally mounted on said lower terminal; one ofsaid cooperating contacts mounted on the other end of said bridge; saidother cooperating contact mounted on said upper terminal; an air putfercomprising a casing and a vane; a first pivot pivotally mounting saidcasing on said bridge; a second pivot pivotally mounting said vane onsaid lower terminal; a third pivot pivotally mounting said vane on saidcasing; said rst, second and third pivot points forming a pantograph forsaid air puter to provide relative motion of said vane with respect tosaid casing.

6. In a circuit breaker' having an upper and lower terminal; a pair ofcooperating contacts `and a bridge; one end of said bridge pivotallymounted on said lower terminal; one of said cooperating contacts mountedon the other end of said bridge; said other cooperating contact mountedon said upper terminal; an `air puier comprising a casing and a vane; afirst pivot pivotally mounting said casing on said bridge; a secondpivot pivotally mounting said vane on said lower terminal; Va thirdpivot pivotally mounting said vane on said casing; said iirst, secondand third pivot points forming a pantograph connection `for said airpuffer whereby movement of said vane is multiplied with respect to saidbridge.

7. In a circuit breaker having an upper and lower terminal; a pair ofcooperating contacts and a bridge; one end of said bridge pivotallymounted on said lower terminal; one of said cooperating contacts mountedon the other end of said bridge; said other cooperating contact mountedon said upper terminal; an `air putter comprising a casing and a vane; afirst pivot pivotally mounting said casing on said bridge; a secondpivot pivotally mounting said vane on said lower terminal; a third pivotpivotally mounting said vane on said casing.

8. In an air putter comprising a casing and a Vane; said casingpivotally mounted on a movable arm of a circuit breaker; said vanepivotally mounted on a terminal of a circuit breaker; said vanepivotally mounted on said casing; said casing having two spaced parallelwalls substantially V-shaped with an arcuate top; a connection betweensaid arcuate top and one side of said spaced parallel walls; said vaneextending between the other sides of said spaced parallel walls; a spoutin said Varcuate connection; said vane moved from the open side of saidcasing during the opening movement of said circuit breaker to therebyforce a stream of air through said spout on the cooperating contacts ofsaid circuit breaker.

References Cited in the le of this patent UNITED STATES PATENTS2,399,485 Harlow et al. Apr. 30, 1946 2,491,964 Frink Dec. 20, 19492,552,427 Heidmann May 8, 1951 2,706,758 Thibaudat Apr. 19, 1955 FOREIGNPATENTS 121,529 Australia June 3, 1946

